Abstract forms with designtime support

A nice article about abstract forms in Visual Studio can be found at Urban Potato. Its useful to download the example project cause the article is well explained but doesnt provide the full code to get the whole impression of the provided technique.
For me it seems a nice solution but doesnt satisfy me to the end: I want to add some controls and moreover some functionality (as protected methods to have access in derived classes) provided by these controls to the abstract base form – but as far as i see its not possible with this approach. Nevermind, read and learn.